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1.
Metabolomics ; 20(5): 107, 2024 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-39306586

RESUMEN

INTRODUCTION: This study focuses on metabolic profiling of a robust marine green algal strain Picochlorum sp. MCC39 that exhibits resilient growth under diverse outdoor open pond conditions. Given its potential for producing high-value chemicals through metabolic engineering, understanding its metabolic dynamics is crucial for pathway modification. OBJECTIVES: This study primarily aimed to investigate the metabolic response of Picochlorum sp. to environmental changes. Unlike heterotrophs, algae are subject to diurnal light and temperature, which affect their growth rates and metabolism. Using an environmental photobioreactor (ePBR), we explored how the algal strain adapts to fluctuations in light intensities and temperature within a simulated pond environment. METHODS: We performed a reverse phase ion pairing-LC/MS-MS based metabolome profiling of the MCC39 strain cultivated in simulated pond conditions in ePBR. The experimental setup included diurnal and bi-seasonal variations in light intensities and temperature. RESULTS: The metabolome profile revealed significant differences in 85 metabolites, including amino acids, carboxylic acids, sugar phosphates, purines, pyrimidines, and dipeptides, which exhibited up to 25-fold change in relative concentration with diurnal variations. Seasonal variations also influenced the production of storage molecules, revealing a discernible pattern. The accumulation pattern of metabolites involved in cellular wall formation and energy generation indicated a well-coordinated initiation of photosynthesis and the Calvin cycle with the onset of light. CONCLUSION: The results contribute to a deeper understanding of the adaptability and metabolic response of Picochlorum sp., laying the groundwork for future advancements in algal strain modification.


Asunto(s)
Luz , Metaboloma , Metabolómica , Estaciones del Año , Temperatura , Metabolómica/métodos , Chlorophyta/metabolismo , Espectrometría de Masas en Tándem , Cromatografía Liquida/métodos
2.
Int J Pharm ; 613: 121414, 2022 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-34952149

RESUMEN

Drug-eluting contact lens can substitute the multiple eye drop therapy. However, loading hydrophobic drug like cyclosporine in the contact lens is very challenging, due to low drug uptake (via soaking method); and alteration in the swelling and optical properties which restricts its clinical application. To address the above issues, graphene oxide (GO, large surface area with oxygen containing functional groups) was incorporated in the contact lenses during fabrication. These GO-laden contact lenses (SM-GO-Cys) as well as blank contact lenses (SM-Cys) were soaked in the solution of cyclosporine. Alternatively, cyclosporine-laden contact lenses (DL-Cys-20) and cyclosporine-GO-laden contact lenses (DL-Cys-20-GO) were fabricated by adding drug and drug-GO (at various level of GO) during fabrication, respectively. Contact angle and swelling data showed increase in water holding capacity of GO laden contact lenses. Optical property was significantly improved due to molecular dispersion of drug on the surface of GO sheets. The drug uptake and in vitro release profile was improved with GO-laden contact lenses by soaking method (SM-GO-Cys-400n) due to hydrophobic interactions between GO and drug. Adding cyclosporine-GO (DL-Cys-20-GO-800n) during fabrication significantly improved drug release kinetics with higher drug leaching (during extraction and sterilization) due to increased swelling, improved dissolution and molecular dispersion of drug on GO sheets. Ocular irritation and histopathological studies demonstrated the safety of GO-contact lens. The in vivo drug release studies in the rabbit eye showed significant improvement in mean residence time (MRT) and area under the curve (AUC) using DL-Cys-20-GO-800n contact lens compared to eye drop solution with reduction in protein adherence value. The study demonstrated that the incorporation of GO into the contact lens can control the release of cyclosporine as well as improved the lens swelling and transmittance properties.


Asunto(s)
Lentes de Contacto , Grafito , Animales , Ciclosporina , Hidrogeles , Conejos
3.
World J Microbiol Biotechnol ; 37(11): 182, 2021 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-34580746

RESUMEN

Microalgae offer a promising source of biofuel and a wide array of high-value biomolecules. Large-scale cultivation of microalgae at low density poses a significant challenge in terms of water management. High-density microalgae cultivation, however, can be challenging due to biochemical changes associated with growth dynamics. Therefore, there is a need for a biomarker that can predict the optimum density for high biomass cultivation. A locally isolated microalga Cyanobacterium aponinum CCC734 was grown with optimized nitrogen and phosphorus in the ratio of 12:1 for sustained high biomass productivity. To understand density-associated bottlenecks secretome dynamics were monitored at biomass densities from 0.6 ± 0.1 to 7 ± 0.1 g/L (2 to 22 OD) in batch mode. Liquid chromatography coupled with mass spectrometry identified 880 exometabolites in the supernatant of C. aponinum CCC734. The PCA analysis showed similarity between exometabolite profiles at low (4 and 8 OD) and mid (12 and 16 OD), whereas distinctly separate at high biomass concentrations (20 and 22 OD). Ten exometabolites were selected based on their role in influencing growth and are specifically present at low, mid, and high biomass concentrations. Taking cues from secretome dynamics, 5.0 ± 0.5 g/L biomass concentration (16 OD) was optimal for C. aponinum CCC734 cultivation. Further validation was performed with a semi-turbidostat mode of cultivation for 29 days with a volumetric productivity of 1.0 ± 0.2 g/L/day. The secretomes-based footprinting tool is the first comprehensive growth study of exometabolite at the molecular level at variable biomass densities. This tool may be utilized in analyzing and directing microalgal cultivation strategies and reduction in overall operating costs.


Asunto(s)
Cianobacterias/crecimiento & desarrollo , Cianobacterias/metabolismo , Microalgas/crecimiento & desarrollo , Microalgas/metabolismo , Secretoma/metabolismo , Biocombustibles , Biomasa , Técnicas de Cultivo de Célula , Microalgas/citología , Nitrógeno , Fósforo , Agua
4.
Colloids Surf B Biointerfaces ; 208: 112096, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34530331

RESUMEN

Ocular drug delivery using contact lenses may be able to substitute for eye drop therapy. However, issues with hydrophobic drugs (like bimatoprost that is used to treat glaucoma) such as low drug uptake using a simple soaking method into preformed contact lenses and alteration in the swelling and transmittance of lenses restricts the application for drug delivery. This research uses graphene oxide (GO) to control the release of bimatoprost from contact lenses along with improvements in the drug uptake, and lens swelling and transmittance. GO was loaded into silicone hydrogel contact lenses by adding the GO at the same time as lenses were polymerized. These lenses were soaked in bimatoprost. Alternatively contact lenses, either with or without GO, were produced by adding bimatoprost during lens polymerization. GO improved contact lens swelling due to its water binding capacity and lens transmittance due to the molecular dispersion of bimatoprost on the surface of the GO which prevented the local precipitation of the drug. The bimatoprost uptake was not improved in the presence of GO. However, its in vitro release profile was improved. Adding bimatoprost and GO at the same time as lenses were polymerized (DL-GO-BMT) significantly decreased the loss of drug during extraction and sterilization in comparison to contact lenses (DL-BMT) without GO. As the amount of GO was increased, the DL-GO-BMT lenses showed a significant decrease in the burst and cumulative release of bimatoprost. Ocular irritation and histopathology reports demonstrated the safety of GO contact lens. The in vivo pharmacokinetic studies in the rabbit tear fluid showed significant improvement in mean residence time (MRT) and area under the curve (AUC) with DL-GO-0.2 µg-BMT-100 contact lens in comparison to eye drop solution. The study demonstrated that the addition of GO to contact lenses can control the release of bimatoprost as well as improved the lens swelling and transmittance. However, further optimization is needed to modulate the release of drug within the therapeutic level to manage glaucoma.


Asunto(s)
Lentes de Contacto Hidrofílicos , Lentes de Contacto , Grafito , Animales , Bimatoprost , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Conejos
5.
Virol J ; 18(1): 178, 2021 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-34461941

RESUMEN

BACKGROUND: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19 pandemic, has infected more than 179 million people worldwide. Testing of infected individuals is crucial for identification and isolation, thereby preventing further spread of the disease. Presently, Taqman™ Reverse Transcription Real Time PCR is considered gold standard, and is the most common technique used for molecular testing of COVID-19, though it requires sophisticated equipments, expertise and is also relatively expensive. OBJECTIVE: Development and optimization of an alternate molecular testing method for the diagnosis of COVID-19, through a two step Reverse Transcription Loop-mediated isothermal AMPlification (RT-LAMP). RESULTS: Primers for LAMP were carefully designed for discrimination from other closely related human pathogenic coronaviruses. Care was also taken that primer binding sites are present in conserved regions of SARS-CoV2. Our analysis shows that the primer binding sites are well conserved in all the variants of concern (VOC) and variants of interest (VOI), notified by World Health Organization (WHO). These lineages include B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.427/B.1.429, P.2, B.1.525, P.3, B.1.526 and B.1.617.1. Various DNA polymerases with strand displacement activity were evaluated and conditions were optimized for LAMP amplification and visualization. Different LAMP primer sets were also evaluated using synthetic templates as well as patient samples. CONCLUSION: In a double blind study, the RT-LAMP assay was validated on more than 150 patient samples at two different sites. The RT-LAMP assay appeared to be 89.2% accurate when compared to the Taqman™ rt-RT-PCR assay.


Asunto(s)
Prueba de COVID-19/métodos , COVID-19/virología , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , SARS-CoV-2/genética , COVID-19/diagnóstico , Humanos , Transcripción Reversa , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/fisiología , Sensibilidad y Especificidad
6.
ACS Omega ; 5(29): 18148-18154, 2020 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-32743189

RESUMEN

Poly(vinylpyrrolidone) (PVP-K90) is widely used to manage dry eye syndrome (DES). The marketed eye drop solutions (high dose) need frequent instillation, affecting the routine lifestyle of patients. PVP-K90-laden contact lenses can be used to overcome the limitations of eye drop solutions (low bioavailability and frequent instillation). However, the conventional methods of PVP-K90 loading show poor loading capacity and short duration of effect. In the present study, we have developed PVP-K90-coated contact lenses via a short curing approach to increase the PVP-K90 loading capacity with a sustained release profile to manage dry eye syndrome. PVP-K90 was loaded by a soaking method (SM-PVP), direct loading (during fabrication, DL-PVP), a combination of soaking and direct loading (DL-SM-PVP), and a novel coating process (SM-PVP-C and DL-SM-PVP-C). The swelling studies suggested improvement in the water uptake (hydration) property of the contact lenses due to the presence of PVP-K90. The optical transparency was within an acceptable range. The in vitro release of PVP-K90 was in the following order: PVP-coated contact lens (168 h) > DL-SM-PVP (168 h) > DL-PVP (96 h) > SM-PVP (72-96 h). PVP-coated contact lenses showed a high burst effect (lubricating effect) and sustained release (3161-448 ng/h between 24 and 168 h) due to high PVP loading/coating in comparison to the uncoated respective contact lenses (964-113 ng/h between 24 and 96 h). In animal studies, the PVP-K90-coated contact lens showed higher tear volume in comparison to the respective uncoated contact lenses and an eye drop solution. This study demonstrates a novel approach of coating a high amount of PVP-K90 on contact lenses for sustained release to manage several ocular diseases like dry eye syndrome, conjunctivitis, and other ocular injuries.

7.
Mater Sci Eng C Mater Biol Appl ; 112: 110885, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32409042

RESUMEN

A fixed combination of bimatoprost/timolol eye drop solution is used to manage the elevated intra-ocular pressure in glaucoma patients, including individuals whose condition is poorly controlled by monotherapy. Eye drop solutions are generally given in high dose, due to poor ocular bioavailability. The high ocular dose of bimatoprost and timolol lead to hyperaemia and systemic cardiac side effects respectively. Here, we introduce multiple implant-laden contact lenses (IM) to passively deliver timolol, bimatoprost and hyaluronic acid at therapeutically relevant doses without high burst release. The drug-loaded implants were individually implanted in the outer periphery of the silicone contact lenses. Atomic force microscopy showed the smooth surface of the implant contact lens, as the implants were inside the contact lens matrix. The implant lens (IM) showed major loss of drugs [timolol = 60.60%, bimatoprost = 61.75% and HA = 46.03%] during the monomer extraction and wet sterilization, while the option of dry radiation sterilization (IM-R lens) and hydration for 24 h prior to use showed relatively lower loss of drugs [timolol = 16.87%, bimatoprost = 47.95% and HA = 24.41%]. The in-vitro drugs release data of IM-R lens, showed sustained release for 72 h, with low burst release in comparison to the soaked (SM) and direct drug-laden contact lenses (DL). The in vivo drug release data in the rabbit tear fluid showed sustained release using IM-R lens in comparison to the SM lens and eye drop therapy. The burst release with the IM-R lens was many folds reduced, which could bypass the side effects associated with multiple eye drop therapy. The in vivo pharmacodynamic study in the rabbit model showed peak and valley profile with multiple eye drop therapy, while IM-R lens showed prolong reduction in intra ocular pressure (IOP) for 120 h. The study demonstrates the application of implantation technology to deliver multiple drug through contact lenses to treat glaucoma.


Asunto(s)
Bimatoprost/metabolismo , Lentes de Contacto , Portadores de Fármacos/química , Siliconas/química , Timolol/metabolismo , Animales , Bimatoprost/administración & dosificación , Bimatoprost/química , Implantes de Medicamentos/química , Liberación de Fármacos , Ácido Hialurónico/administración & dosificación , Ácido Hialurónico/química , Ácido Hialurónico/metabolismo , Presión Intraocular , Conejos , Propiedades de Superficie , Timolol/administración & dosificación , Timolol/química
8.
Int J Pharm ; 581: 119279, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32240806

RESUMEN

Loading of gatifloxacin in contact lenses affects critical lens properties (optical and swelling) owing to drug precipitation in the contact lens matrix. The presence of Pluronic® F-68 in the packaging solution creates in-situ micelles in the contact lens to dissolve gatifloxacin precipitates and provide sustained drug release. The micelles further improved the drug uptake from the drug-packaging solution to create an equilibrium of drug between the lens matrix and the packaging solution. In this study, we optimized gatifloxacin-pluronic-loaded contact lenses to achieve the desired optical transmittance, swelling, and gatifloxacin loading capacity as well as sustained drug delivery. Optimization of gatifloxacin-pluronic-loaded contact lens was carried out using a 32 factorial design by tailoring the concentration of Pluronic® F-68 in the packaging solution (X1) and the amount of gatifloxacin in the monomer solution (X2) to achieve the desired lens properties. The optimized batch (X1 = 0.3%w/v and X2 = 0.3%w/v) showed an optical transmittance of 92.84%, swelling of 92.36% and gatifloxacin loading capacity of 92.56 µg. The in vitro flux data of the optimized batch (GT-Pl-CL) showed sustained release up to 72 h, whereas soaked contact lenses (SM-CL) and direct gatifloxacin-loaded contact lenses (DL-CL) showed a sustained release up to 48 h. The in vivo gatifloxacin release data for rabbit tear fluid showed sustained release with a high gatifloxacin level for the GT-Pl-CL lens in comparison to the SM-CL and the eye drop solution. This study demonstrates the application of the 32 full factorial design to optimize gatifloxacin-pluronic-loaded contact lenses to achieve the desired optical transmittance, swelling, and drug loading capacity.


Asunto(s)
Lentes de Contacto Hidrofílicos , Sistemas de Liberación de Medicamentos/métodos , Gatifloxacina/farmacocinética , Absorción Ocular/efectos de los fármacos , Soluciones Oftálmicas/farmacocinética , Poloxámero/farmacocinética , Animales , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Liberación de Fármacos/efectos de los fármacos , Liberación de Fármacos/fisiología , Excipientes/administración & dosificación , Excipientes/química , Excipientes/farmacocinética , Femenino , Gatifloxacina/administración & dosificación , Gatifloxacina/química , Masculino , Absorción Ocular/fisiología , Soluciones Oftálmicas/administración & dosificación , Soluciones Oftálmicas/química , Poloxámero/administración & dosificación , Poloxámero/química , Conejos
9.
Colloids Surf B Biointerfaces ; 186: 110681, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31812077

RESUMEN

Psoriasis is a widespread chronic disease affecting 1-3 % of total population. In major cases (>80 %), it is treated by topical application of corticosteroids. However, the topical route is very challenging due to physico-chemical nature of diseased stratum corneum and so no single treatment works for every patient. The oral route showed severe side effects due to systemic immunosuppression, which can be avoided by topical route. The aim of the research work was to investigate cyclosporine loaded microemulsion based gel for effective cyclosporine permeation and retention in the skin tissue for psoriasis treatment. The pseudo ternary phase diagram at three Smix ratios (2:1, 1:1, and 1:2; Tween 80: isopropyl alcohol) were constructed using isopropyl myristate as oil phase. The Smix at 2:1 ratio showed large microemulsion area. The transmission electron microscope images showed spherical non-aggregated oil globules with the size < 50 nm. The selected microemulsion (Cy-2-ME12O55SM) was incorporated in Carbopol 940 gel for topical application. The ex vivo diffusion study showed improved permeation (>24 h) with microemulsion-gel in comparison to cyclosporine suspension. The microemulsion-gel was non-irritating on the rabbit skin. In drug retention studies, microemulsion-gel showed high drug retention (trapping, 38.92 %) in the skin tissue, which was due to destabilization of microemulsion after penetration in the skin layer causing precipitation of cyclosporine. The depot effect due to cyclosporine precipitates could be helpful for sustained effect of cyclosporine for the effective treatment of psoriasis.


Asunto(s)
Ciclosporina/farmacología , Psoriasis/tratamiento farmacológico , Administración Tópica , Animales , Ciclosporina/administración & dosificación , Ciclosporina/química , Emulsiones/administración & dosificación , Emulsiones/química , Emulsiones/farmacología , Geles/administración & dosificación , Geles/química , Geles/farmacología , Concentración de Iones de Hidrógeno , Tamaño de la Partícula , Conejos , Absorción Cutánea/efectos de los fármacos , Solubilidad , Propiedades de Superficie , Termodinámica , Viscosidad
10.
Colloids Surf B Biointerfaces ; 185: 110632, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31735422

RESUMEN

Lidocaine is widely used as a local anaesthetic in the clinical practice to manage pre- and post-operative pain, skin burns, etc. However, the short duration of action (< 2 h) of marketed dosage forms limit their ability to meet clinical needs. Herein, we prepared a lidocaine-tPP(tri potassium phosphate)-complex loaded microemulsion to achieve greater penetration, followed by destabilization of microemulsion in the skin layer to precipitate oil-complex to produce a depot effect in the skin for prolonging the effects of anaesthesia. The lidocaine-tPP-complex-microemulsion was compared with lidocaine base loaded microemulsion, marketed ointment USP and lidocaine HCl. The pseudo ternary phase diagrams at three Smix ratios (1:2, 1:3 and 1:4; Pluronic F127: PEG 400) were constructed using Capmul MCM C8 EP as oil phase. The Smix at 1:4 ratio showed large microemulsion area in comparison to 1:2 and 1:6 ratio. The lidocaine base (LD-1:4-ME10O45SM and LD-1:4-ME20O45SM) and lidocaine-tPP-complex (LDC-1:4-ME10O45SM and LDC-1:4-ME20O45SM) loaded microemulsion batches (1:4 ratio) were thermodynamically stable. The ex vivo diffusion study showed sustained release up to 12 h with microemulsion batches, in comparison to lidocaine HCl (4 h) and ointment base (7 h). The selected LDC-1:4-ME20O45SM batch was non-irritating on the rabbit skin. In drug retention studies, LD-1:4-ME20O45SM and LDC-1:4-ME20O45SM batches showed 2.68- and 3.93-fold greater lidocaine retention in comparison to ointment USP. The radiant heat tail-flick test showed prolong local anaesthesia using LDC-1:4-ME20O45SM in comparison to ointment USP. The findings suggest that lidocaine-tPP-complex loaded microemulsion could be a potential strategy for providing prolong local anaesthesia.


Asunto(s)
Anestesia Local , Emulsiones/química , Lidocaína/farmacología , Polifosfatos/farmacología , Analgésicos/farmacología , Anestésicos Locales/farmacología , Animales , Colorantes/química , Difusión , Conductividad Eléctrica , Cabras , Concentración de Iones de Hidrógeno , Masculino , Tamaño de la Partícula , Transición de Fase , Conejos , Ratas Wistar , Piel/efectos de los fármacos , Pruebas de Irritación de la Piel , Electricidad Estática , Termodinámica , Viscosidad
11.
Int J Pharm ; 566: 513-519, 2019 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-31175992

RESUMEN

The optical and swelling properties of gatifloxacin-loaded contact lens decrease owing to the precipitation of gatifloxacin (on hydration) in the matrix structure of the contact lens. This paper focuses on the use of Pluronic F68 both inside and outside (in the packaging solution) the contact lens to form micelles to dissolve the gatifloxacin precipitates and not limited to sustain the release of gatifloxacin. The aim of this study was to screen the critical variables affecting the optical and swelling properties of gatifloxacin-loaded contact lens. The independent variables investigated were the concentration of Pluronic F68 incorporated in the monomer solution to fabricate the lens (X1, %w/v), the concentration of Pluronic F68 in the packaging solution (X2, %w/v), the concentration of gatifloxacin incorporated in the monomer solution (X3, %w/v), the concentration of gatifloxacin incorporated in the packaging solution during autoclave (X4, %w/v), the concentration of gatifloxacin incorporated in the packaging solution during extraction (X5, %w/v), the time (stabilization time) after the addition of gatifloxacin and Pluronic F68 to the monomer solution before the fabrication of the lens (X6, h), the pH of the packaging solution (X7), the temperature of the extracted solution (X8, °C), and the curing time for fabricating the contact lens (X9, min). The gatifloxacin-loaded contact lenses were characterized for their optical transmittances after sterilization on day 1 (Y1, %), optical transmittances after 7 days of sterilization (Y2, %) and swelling percentages after 7 days of sterilization (Y3, %). The selected variables showed responses that were in the ranges 53.5% to 97.2%, 51.3% to 92.6%, and 50.3% to 83.7% for Y1, Y2, and Y3, respectively. The data suggest that the presence of Pluronic F68 inside the contact lens (X1) reduced the optical and swelling properties of the contact lens, whereas the presence of Pluronic F68 in the packaging solution (X2) improved them through micelle formation. The other variables (X3 to X9) did not exhibit significant effects on the swelling and transmittance. This study revealed the potential of Plackett-Burman design to screen the selected critical variables that affected the optical and swelling properties of gatifloxacin-loaded contact lens.


Asunto(s)
Lentes de Contacto , Gatifloxacina/química , Poloxámero/química , Preparaciones de Acción Retardada/química , Diseño de Fármacos , Embalaje de Medicamentos , Micelas , Esterilización
12.
Acta Biomater ; 86: 350-362, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30625414

RESUMEN

Contact lenses are ideally suited for extended drug delivery to the ocular tissues, but incorporation of any particulate system affects the critical properties of the contact lens. Timolol loading by the conventional soaking method does not significantly alter the critical properties of the contact lens. However, there are challenges of low drug loading and high burst release. This research work aimed to investigate the effect of gold nanoparticles (GNPs) on loading and its release kinetics from the contact lens using the soaking method. In one approach, GNPs were loaded into the timolol soaking solution (GNPs-SS), and in another approach, GNPs were incorporated into the contact lenses (GNPs-CL) during fabrication. The contact lenses were soaked at two different concentrations of timolol (i.e., 2 mg/ml and 4 mg/ml). Swelling and optical transmittance were not significantly affected by the presence of GNPs in the contact lenses. A significant uptake/loading of timolol using the GNPs in both the approaches was observed. The in vitro flux data showed no significant improvement in the release rate profiles of timolol when using both approaches. However, the in vivo study in the rabbit tear fluid showed high timolol concentration with the GNPs-laden contact lens at all timepoints in comparison to the soaked contact lenses without GNPs. The in vivo pharmacodynamic study in rabbits showed a 2 mmHg average fall in intraocular pressure (72 h) using the GNPs-laden contact lenses, while the soaked contact lenses without GNPs and eye drops solution (0.5 %w/v) showed 2 mmHg. The drug distribution study in the ocular tissue showed a significant improvement in the drug deposition with the GNPs-laden contact lenses in the ciliary muscle and conjunctiva. This study successfully demonstrated the potential of GNPs to enhance the uptake of drug from the drug soaking solution to treat glaucoma without compromising the critical properties of contact lens. STATEMENT OF SIGNIFICANCE: In this study, we have overcome the limitation of the conventional soaking method of low drug loading and high burst release from the contact lenses. We have investigated the effect of gold nanoparticles (GNPs) on the timolol loading and its release kinetics from the contact lenses. The study revealed the potential of GNPs to enhance the uptake of timolol from the timolol soaking solution to treat glaucoma without compromising the critical lens properties.


Asunto(s)
Lentes de Contacto , Liberación de Fármacos , Oro/química , Nanopartículas del Metal/química , Timolol/farmacología , Animales , Ojo/efectos de los fármacos , Ojo/metabolismo , Presión Intraocular/efectos de los fármacos , Cinética , Nanopartículas del Metal/ultraestructura , Conejos , Distribución Tisular/efectos de los fármacos
13.
Int J Pharm ; 548(1): 139-150, 2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-29960036

RESUMEN

Currently, bacterial conjunctivitis is treated by frequent administration of antibiotic eye drop solutions, which is tedious and patient noncompliant. Contact lenses could be ideal medical devices to sustain the release of ophthalmic drugs, but the incorporation of the latter can alter the optical and physical properties of the lenses. In addition, many contact lens users have reported the pink eye syndrome, making them unsuitable as ocular medical devices. In the present study, we have designed a novel type of lenses containing semi-circular rings loaded with moxifloxacin HCl (a broad spectrum antibiotic) and hyaluronic acid (a comfort agent), respectively, in order to treat bacterial conjunctivitis without altering the critical lens properties. The drug loaded rings were implanted separately within the periphery of the contact lenses using the modified cast moulding technology. The atomic force microscopy report showed an average roughness of 22.27 nm for the implant lens, which was significantly lower in comparison to the marketed Freshlook® (116.27 nm) contact lens. The major amount of moxifloxacin HCl was leached (68.16-74.55%) during the monomer extraction and wet sterilization (autoclave) steps; hence the lenses were terminally sterilized by radiation and packaged under dry condition (dehydrated). The in vitro release data showed release for moxifloxacin HCl and hyaluronic acid up to 96 h. The in vivo drug release studies showed significant improvement [>MIC for Staphylococcus aureus] in the drug residence time in comparison to the eye drop therapy. The in vivo efficacy study in the staphylococcus aureus induced conjunctivitis showed equivalent healing effect with the single implant contact lens in comparison to the frequent high dose eye drop therapy. The study demonstrated the successful application of the implantation technology to co-deliver moxifloxacin HCl and hyaluronic acid from the contact lenses for the extended period of time to treat conjunctivitis.


Asunto(s)
Antibacterianos/administración & dosificación , Conjuntivitis Bacteriana/tratamiento farmacológico , Lentes de Contacto , Sistemas de Liberación de Medicamentos , Fluoroquinolonas/administración & dosificación , Ácido Hialurónico/administración & dosificación , Animales , Antibacterianos/química , Liberación de Fármacos , Femenino , Fluoroquinolonas/química , Ácido Hialurónico/química , Masculino , Moxifloxacino , Conejos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo
14.
PLoS One ; 9(9): e106457, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25207648

RESUMEN

Cellular metabolite analyses by (13)C-NMR showed that C. reinhardtii cells assimilate acetate at a faster rate in heterotrophy than in mixotrophy. While heterotrophic cells produced bicarbonate and CO2aq, mixotrophy cells produced bicarbonate alone as predominant metabolite. Experiments with singly (13)C-labelled acetate ((13)CH(3)-COOH or CH(3)-(13)COOH) supported that both the (13)C nuclei give rise to bicarbonate and CO2(aq). The observed metabolite(s) upon further incubation led to the production of starch and triacylglycerol (TAG) in mixotrophy, whereas in heterotrophy the TAG production was minimal with substantial accumulation of glycerol and starch. Prolonged incubation up to eight days, without the addition of fresh acetate, led to an increased TAG production at the expense of bicarbonate, akin to that of nitrogen-starvation. However, such TAG production was substantially high in mixotrophy as compared to that in heterotrophy. Addition of mitochondrial un-coupler blocked the formation of bicarbonate and CO2(aq) in heterotrophic cells, even though acetate uptake ensued. Addition of PSII-inhibitor to mixotrophic cells resulted in partial conversion of bicarbonate into CO2(aq), which were found to be in equilibrium. In an independent experiment, we have monitored assimilation of bicarbonate via photoautotrophy and found that the cells indeed produce starch and TAG at a much faster rate as compared to that in mixotrophy and heterotrophy. Further, we noticed that the accumulation of starch is relatively more as compared to TAG. Based on these observations, we suggest that acetate assimilation in C. reinhardtii does not directly lead to TAG formation but via bicarbonate/CO2(aq) pathways. Photoautotrophic mode is found to be the best growth condition for the production of starch and TAG and starch in C. reinhardtii.


Asunto(s)
Acetatos/metabolismo , Bicarbonatos/metabolismo , Espectroscopía de Resonancia Magnética con Carbono-13 , Chlamydomonas reinhardtii/metabolismo , Procesos Autotróficos , Transporte Biológico , Chlamydomonas reinhardtii/citología , Chlamydomonas reinhardtii/crecimiento & desarrollo , Procesos Heterotróficos , Almidón/biosíntesis , Triglicéridos/biosíntesis
15.
J Basic Microbiol ; 49(6): 593-7, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19810043

RESUMEN

Superoxide dismutase (SOD) and catalase expression is associated with oxidative stress. Existing techniques for the individual staining of SOD and catalase have been described in the past. The objective of this study was to achieve a simple and rapid technique for the double staining of bacterial SOD and catalase on the same polyacrylamide gel. SOD detection was carried out using nitro-blue tetrazolium (NBT) dye reduction followed by ferricyanide precipitation for negative staining of the catalase enzyme on the same gel. The staining procedure resulted in pale blue SOD bands while catalase appeared as yellow bands against a greenish blue background on the same gel. This technique was used to detect changes in the polymorphic forms of these enzymes in Deinococcus radiodurans R1 and Kocuria sp. C2 subjected to stresses like UV and gamma radiation and desiccation.


Asunto(s)
Catalasa/metabolismo , Deinococcus/enzimología , Micrococcaceae/enzimología , Coloración y Etiquetado/métodos , Superóxido Dismutasa/metabolismo , Electroforesis en Gel de Poliacrilamida/métodos , Ferricianuros/metabolismo , Nitroazul de Tetrazolio , Estrés Oxidativo , Isoformas de Proteínas/metabolismo
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